Small alternator



Sept. 22, 1964 R. B. CLARK 3,150,278

SMALL ALTERNATOR Filed May 19, 1959 2 Sheets-Sheet l INVENTOR.

RICHARD B. CLARK 4p iii' ATTO Sept. 22, 1964 R. B. CLARK SMALL ALTERNATOR Filed May 19, 1959 2 Sheets-Sheet 2 INVENTOR.

RICHARD B. CLARK United States Patent 3,150,278 SMALL ALTERNATQR Richard B. Clark, Sidney, N.Y., assignor to The Bendix Corporation, a corporation of Delaware Filed May 19, 1959, Ser. No. 814,330 7 Claims. (Cl. Slit-89) This invention relates to an ignition system for an internal combustion engine of the spark ignited type. More particularly, the invention relates to an improved current generating alternator and distributor for such system, and to the combination of such alternator and distributor with elements of an ignition system including an externally mounted voltage step-up coil.

The invention has among its objects the provision of improved current generating alternators for an engine ignition system, the alternator being particularly characterized by its compactness, simplicity, and the ease with which it may be assembled and serviced.

A further object of the invention lies in the provision of an alternator which is easily adaptable to being mounted upon various diiferent engines, and to being mounted in various positions and driven in various manners as re quired.

Yet another object of the invention lies in the provision of an improved combined alternator of the type described and a distributor mounted in the same housing as the alternator.

Further objects of the invention include, in apparatus of the type described, the provision of an improved manner for retaining the field assembly in the alternator housmg.

The above and further objects and novelfeatures of the invention will more fully appear from the following description when the same is read in connection with the accompanying drawings. It is to be expressly understood, however, that the drawings are for the purpose of illustration only, and are not intended as a definition of the limits of the invention.

In the drawings, wherein like reference characters refer to like parts throughout the several views,

FIG. 1 is a view in axial longitudinal section through a preferred embodiment of a combined alternator'and distributor made in accordance with the invention;

FIG. 2 is a view in end elevation of the apparatus of FIG. 1 with the distributor cover removed therefrom, the view being taken in the direction from left to right in FIG. 1;

FIG. 3 is a view in transverse section through the field coil assembly and the rotor of the apparatus of FIG. 1, the section being taken generally along line 3-3 of FIG. 1;

FIG. 4 is a view in longitudinal axial section through the field assembly of the alternator, the section being taken generally along the line 44 of FIG. 3;

FIG. 5 is a somewhat diagrammatic View in side elevation of an internal combustion engine of the spark ignited type incorporating an ignition system in accordance with the invention;

FIG. 6 is a view in longitudinal axial section through a voltage step-up coil which may be employed in the ignition system of FIG. 5, certain of the parts being shown in elevation; and

FIG. 7 is a somewhat schematic wiring diagram of the ignition system of FIG. 5.

The combined alternator and distributor of the invention, of which a preferred embodiment is illustrated herein, may advantageously be employed with a number of different internal combustion engines of the spark ignited type. Such combined alternator and distributor is generally circular cylindrical and is substantially symmetrical about its longitudinal axis. Because of its compactness,

such unit may readily be mounted in a small space, as in a cramped engine compartment, and may be driven in any convenient manner in synchronism with the crank shaft, as by being drivingly connected to the cam shaft of the engine. The ignition system of the invention employs a voltage step-up coil located externally of the alternator and distributor unit in any convenient location, preferably in the engine compartment. The ignition system and the combined alternator and distributor of the invention thus provide a maximum of flexibility in its use with engines of various design.

Turning now to the drawings, the combined alternator and distributor shown herein is designated generally by the reference character 10. Unit 10 has two main sections, the first of which, designated 11, is the alternator section, and the second of which, designated 12, i the distributor section. Sections 11 and 12 are disposed coaxially of each other and are generally contained within a metallic casing or housing having two end-abutted sections 14 and 15. Such housing sections, which are held together in alignment in a manner to be described, journalthe main shaft 16 of the alternator and distributor in bearings 17 and 20. As shown, housing section 15 has an end wall 19 which carries a central boss with the bearing 17 therein. Housing section 14 has an inner transverse wall or partition 21 carrying the bearing 20 therein.

Secured to shaft 16, within the alternator portion 15 of the housing, is a circular cylindrical permanent magnet 22 through which shaft 16 extends axially. Two generally U-shaped rotor shoe members 24 and 25 are disposed on shaft 16 at opposite ends of magnet 22, the shoe means 24 and 25 facing in opposite directions and being displaced from each other so that the longitudinally directed shoe pieces of means 24 and 25 overlie the permanent magnet 22, are radially spaced from the magnet, and are interdigitated.

Within alternator portion 15 of the housing, there is disposed a field assembly 26 having a generally annular transversely laminated field core 27 snugly received within an annular seat 29 in housing portion 15. As shown more clearly in FIG. 3, the field core 27 has four radially inwardly projecting legs 30, there being a field coil 31 disposed about each of legs 30. To maintain field core 27 from rotation, at a longitudinally extending outer edge zone there is provided a slot 32 which receives the inwardly projecting end of a longitudinally extending pin 34 secured to housing portion 15, as shown in FIG. 1.

In order to maintain field coil assembly 26 from any substantial movement longitudinally of the alternator housing, at least one of the metal laminations making up the field core is bent out of its plane so that when relaxed the field core has an axial length appreciably greater than its axial compacted length. Preferably the bent lamination is either one of the end laminations; in FIG. 4 it is the left hand outer lamination which is bent axially from its plane to form a plurality of bends 35. If desired, the other end lamination may be similarly bent.

The joint between housing portions 14 and 15, generally designated 33, has a relatively short axially extending flange on housing portion 14, such flange extending into the outer end of seat 29. When the field coil assembly is mounted in seat 29 and the housing parts are assembled as shown, the tightening up of the retaining studs between the housing portions, one of which is shown at 38, causes the bent lamination or laminations of the field core to be flattened, and thus resiliently to hold the field core against endwise motion in the seat 29.

In the recess at the outer end of the distributor portion 14, there are located a breaker assembly 37 and a distributor assembly. The breaker assembly includes a cam 36 mounted on shaft 16, such cam cooperating with a conventional breaker arm mounted on a post 39 which partment.

central high tension contact 45 and distributes high voltage discharges delivered to such centercontact in a manner to be described to the respective outer terminals 46 as the finger 44 rotates therepast.

In FIG. there is shown one convenient form of mounting for the alternator 10. The engine 56 thereshown is of the four cylinder, four-cycle type, wherein.

the camshaft 59 is driven at one-half the speedof crank shaft '57. The alternator 11 which is driven at the same speed as camshaft 59 through 'drive means 60, is

thus of the four pole type shown in FIGS. 14, inclusive.

The breaker cam 36 has four equally spaced rises or lobes thereon. The distributor portion of the alternator, therefore, functions to direct high tension electrical impulses through wires 48, connected to outer terminals 46, in the proper sequence andtimed relationship to the respective spark plugs 49 of the engine.

a The central terminal 450i thedistributor is connected by a wire 50 to the output of the secondary 51 of a voltage step-up coil 47, whichis externally mounted at a convenient location, for example, in the engine com- The primary 52 of coil 47 is supplied by the alternator it the contacts 42 of thebreaker assembly 37 being interposed in a circuit which selectively grounds the wire 54 leading from the alternator to the primary 52 of the coil 47. r

FIG. 7 shows the manner in which the components of the alternator are connected, and also the manner in which the alternator is connected to the other circuits of the engine. As there shown, the four field coils 31 are serially connected, one end of such circuit being connected to ground, that is, the frame of the alternator, and the other end being connected to the delivery wire 54. The breaker contacts 42 are interposedin a circuit which alternately closes the field coil circuit and opens such circuit, therebyto allow the delivery of a pulse of electrical energy to the primary 52 of coil 47. The secondary 51 ofsuch coil is connected, as shown, to the central contact of the distributor, the distributor functioning as a rotary switch selectively electrically connecting central contact 45 to the respective outer contact 46.

The combined alternator and distributor of the present invention is shown as being employed in an ignition system employing one voltage step-up coil. It is to be understood, however, that the device of the invention may readily be adaptedvto use in a system wherein a separate voltage step-up coil is employed-for each engine cylinder. tributor of the device are wired so that the primary of each coil is fed with a pulse of low tension current at In such system the breaker points and disthe proper time, the coils steppingup the voltage of such I pulses so as to create electrical discharges at the respective spark plugs.

Although only one embodiment of the invention has been illustrated in the accompanying drawings and described in the foregoing specification, it is to be especially understood that various changes, such as in the relative dimensions of the parts, materials used and the like, as well as the suggested mannerof use of the apparatus of the invention, may be made therein without departing from the spirit and scope of the invention as will now be apparent to those skilled in the art.

What is claimed is:

1. In electrical apparatus, a housing comprising first and second members, said first member having a bore of uniform diameter terminating at a radial shoulder, an annular field core slidably mounted in and closely fitting said bore throughout the length of the core, the inner end of the latter being seated against said shoulder, said second member being in end-to-end abutment with said first member and having an axially extending pilot portion slidably extending into said bore against the other endof said core, and means for securing said members in assembled relation. V

2. In electrical apparatus, a housing comprising first and second members, said first member, having a bore of uniform diameter in one end thereof terminating at its inner end at a radial shoulder and said second member 7 being in end-to-end abutment with said first member and having an axially extending pilot portion slidablyextending into said bore, an annular field core slidably mounted in and closely fitting said bore throughout the entire length of the core with a peripheral portion thereof closely confined between said shoulder and said pilot portion, and means for securing said members in assembled relation. V

3. In electrical apparatus, a housing comprising first and second members, said'first member having a ,bore terminating at a radial shoulder and said second member ,being in end-to-end abutment with said first member and having an axially extending pilot portion extending into said bore, an annular field core slidably mounted in said bore with a peripheral portion thereof confined between said shoulder and said pilot portion, means for securing said members in'assembled relation, and re silient means under compression for holding said core against axial movement between said shoulder and said pilot portion.

4. Electrical apparatus as claimed in claim 3, whereinsaid resilient means isan annular wavy spring.

5. Electrical apparatus as claimed in claim 3, wherein said core is laminated and said resilient means comprises a deformed'lamina of said core.

6. Electrical apparatus as claimed in claim 3 wherein said core has a plurality of circumferentially spaced, inwardly extending radial poles, and comprising a coil Wound on each of said poles.

7. Electrical apparatus as claimed in claim 6, wherein said core is laminated and the laminations thereof are held in assembled relation by. said coils and said housing ,member s.

References Cited in the file of this patent UNITED STATES PATENTS 1,554,438 Lee Sept. 22, 1925 1,577,976 Knowlson Mar. 23, 1926 1,674,876 Thompson June 26, 1928 2,234,926 Jepson Mar. 11, 1941 2,493,414 Morrison Jan. 3, 1950 2,552,023 Andresen May 8, 1951 2,655,611 Sherman Oct. '13, 1953 2,713,128 Toifolo July 12, 1955 2,749,458 Buchmann June 5, 1956 2,761,987 Bechwith Sept. 4, 1956 2,866,912 Williamson Dec. 30, 1958 2,871,384 Gabriel Jan. 27, 1959 2,918,796 Weis Dec. 29, 1959 FOREIGN PATENTS 862,331 France Nov. 30, 1940 962,064 France NOV. 28, 1949 

1. IN ELECTRICAL APPARATUS, A HOUSING COMPRISING FIRST AND SECOND MEMBERS, SAID FIRST MEMBER HAVING A BORE OF UNIFORM DIAMETER TERMINATING AT A RADIAL SHOULDER, AN ANNULAR FIELD CORE SLIDABLY MOUNTED IN AND CLOSELY FITTING SAID BORE THROUGHOUT THE LENGTH OF THE CORE, THE INNER END OF THE LATTER BEING SEATED AGAINST SAID SHOULDER, SAID SECOND MEMBER BEING IN END-TO-END ABUTMENT WITH SAID FIRST MEMBER AND HAVING AN AXIALLY EXTENDING PILOT PORTION SLIDABLY EXTENDING INTO SAID BORE AGAINST THE OTHER END OF SAID CORE, AND MENS FOR SECURING SAID MEMBERS IN ASSEMBLED RELATION. 